Step 1: (Finding a feather)
          Locate a primary feather (wing tip) from as large a bird as you are able.  A goose or turkey feather might be easy to find, and they will do just fine as a quill pen; as they have done so for many centuries.
          There are many feathers to choose from online if you don't have a goose or turkey living in your backyard, or a bird ranch nearby.  The feathers should not cost very much in either case.  You can also find feathers at some hobby shops.
          If you are righthanded, you will want a feather from the left wing.  If you are lefthanded, you will want a feather from the right wing.  This can be determined by the arch the quill takes in your hand, and will provide comfort by taking advantage of that natural curve to the feather.

Step 2: (Removing the barbs)
          Now that you have your feather, cut back the plume, or barbs near the tip if you haven't already done so.  This way the pen will be more comfortable to use.  This is a matter of choice.  If you like the plume, keep it.  You can always change your mind later.

Step 3: (Preparing the feather)
          Quills are just fine as they come from the bird, but they can be toughened up and improved with various processes.
          One way to improve a quill, to make it last longer, and be more flexible in use, is to place your quills up to the barbs in boiling water, and let them soak for a few minutes.
          Another way, and a good second process if you have used the boiling water process, is to fill a 14 ounce can (398 ml) with sand, heat it in your oven to about 325 degrees, and then stick the quills into the hot sand up to the plume and barbs.  Leave them until the sand returns to room temperature.
          With this done, the quills are now strong and pliable enough to carve without splitting or shattering.  They will also write more lines before needing the help of a nibmeister*.

Step 3: (Cutting the tip)
          Now cut the tip of the quill off.  Cut it at a 45 degree angle away from you.  You need to place the quill tip firmly on a cutting board with the top of the pen up and away from the cutting board.

Step 4: (Cutting the slit)
          Now place an Exacto knife, or pen knife under the upperside of the quill and lever up just a smidgin to create the slit that will draw the ink to the tip of the nib.  Remember: 'just a smidgin'.  You can always lengthen it if you feel the need, and, keep in mind, it is easy to split the quill too much if you press your luck.

Step 5: (Preparing the feather)
          Now you cut away half the bottom side of the quill; cutting perpendicular to the shank of the quill.  You need to leave enough of the quill to form the shoulders of the nib.  This is also a good time to clean the quill out of any goo that might be inside it.

Step 6: (Carving the nib)
          Shaping the shoulders of the nib can be done with a pen knife, Exacto knife, or a pair of very small curved scissors.  Copy the shape below as best you can, and remember to include the bevel on the topside of the nib.
          You will find your favorite shape as you make more pens.

Enjoy!!

*  Nibmeisters are master repairers and servicers of fountain pens, nib pens, and quills; anything that uses a nib, and is mechanical; writers not included.